16 Best CSS and JavaScript Libraries for Web Developers

Whether you're building a static website through plain HTML & CSS or using a responsive framework to build a dynamic portal, user interface plays an important role in retaining and converting the visitors. Frameworks do provide a base for making the foundation of a website, but when it comes to building a rich and interactive interface, a web developer always looks for an extensive UI library. A ready-made library not only speeds up the entire development process but also enables you to experiment conveniently with multiple versions of the primary design. We're going to see some of the handpicked CSS and JavaScript libraries that provide a rich set of web interface elements commonly used on business websites. These libraries are easy-to-use and give you enough options to optimize the user experience significantly.iUI Web Framework - This is a powerful UI library for developing apps for various popular mobile platforms like iOS and Android. The interface built through this library renders perfectly on almost every tablet device. You can easily fork it on GitHub to come up with a completely customized and extended version of the same. It has an extensive collection of ready-made interface elements that can be used and customized as per the project requirement. If you have a working knowledge of HTML & CSS, this library can get you started very quickly helping you build impressive app designs. You can also use ready-made themes available with this library.

Performer - It's a popular JavaScript and CSS library ideal for professional web developers. It has a rich set of interface components that can be used and modified for your project. Beginners can also use it easily due to extensive documentation and collection of demos. Through this library, you can create an interactive sign-up form and landing pages. It's extremely lightweight and fast and does not affect your website's speed. To use this library, you'll never need to write a single line of JavaScript code as the entire interface elements are available in the form of CSS classes. You just need to use the right class at the right place in your general HTML code.

AliceJS - This unique JavaScript library uses available hardware acceleration capabilities of end-user system to render advanced graphics effects using CSS3. It's ideal for portfolio or similar websites where photos or graphical elements are used extensively. You can even create your own plugins through this library. Creating different types of CSS3 animations is a cakewalk with the help of this library. For using AliceJS, you never need to rely on an external library as it works independently without any dependencies. The visual effects created through this library also renders perfectly on BlackBerry and iOS platforms without any errors.

YUI Library - This popular and widely used JavaScript and CSS library is a perfect recipe for creating awesome visual components of your website. This library is used by several big companies to power their business websites. Since it is open source with the large and active community, beginners planning to use it can easily grasp its application. It has a rich array of commonly used interface elements that can be easily incorporated into your existing web design. You can also find dozens of tutorial videos for this library on YouTube. Since this library is extremely large, it may take some time to get familiar with all the available options and features.

Modernizr - If you're building a website with HTML5 and CSS3, then this library can be a lifesaver for you. This extremely useful library detects all the features and properties present in the visitor's browser, which are then populated in a JavaScript object for your usage. This helps you in the conditional rendering of the web page depending on the available features within the browser. It also has the in-built facility to conditionally load select CSS and JavaScript files. Developers often use this library to avoid loading of scripts until their actual usage is required. It also helps in the correct usage of CSS3 and HTML5 features that are supported by the user's browser.

LivePipe - This is a rich JavaScript library that lets you program various interface components including events associated with each of the element. If your website includes a lot of interactive user controls, you must use this library to control the associated events in a better and optimized way. This will not only give a better experience to the visitor but will also help you program non-obtrusive interface elements within your website. You can also maintain cookies related to interface elements very easily through this library. For each interactive control, this library has a complete set of API calls for easy management of the runtime behavior.

Metro UI CSS - If you're a fan of Windows 8 rich metro user interface, then you can use this powerful and easy-to-use library to give a same look 'n' feel to your website. It lets you build a responsive website with Metro UI elements in no time. This library contains a rich set of metro icons and interface-elements to quickly create impressive landing and squeeze pages. It also has a collection of advanced web interface controls like sliders and progress bars to make your website visually appealing. It also has a strong support for typography to customize content-heavy sections on the home page. It's one of my favorite UI libraries for web projects.

Ember.js - This popular library provides a complete UI framework to quickly design visually appealing websites. It has a rich set of functions and classes to design complex web projects with advanced user interface elements. Despite having a large set of API calls, the entire framework is light and does not slow the website. This library uses modular approach so that you only use those parts of the entire library that are actually needed for the project. This library is used by several popular websites that receive decent traffic providing excellent user experience through rich web page elements rendered through this flexible JavaScript library.

Zebra UI Library - This object-oriented JavaScript library provides you with a collection of functions to integrate rich web UI to your website. Interface elements created through this library renders well both on desktops and mobiles. It has over 3 dozen rich UI elements and controls to create highly interactive and user-friendly web pages. You can also extend and can create new interface elements through this library that makes it one of the powerful web developing resources that are easily extensible. New users can get started with zebra library within few minutes as the usage is very simple and is devoid of any kind of complex configuration.

jQuery UI - It is one of the easiest and extremely flexible UI libraries for web developers. You can do event handling, widget creation and interface element transition very easily through it. The collection of interface widgets helps you integrate them quickly at the desired place in a web page. You can also add various visual effects to various page elements like animation, fade off and much more. It also includes a powerful utility called 'Widget Factory' that lets you create your own widgets to extend the existing library for custom design solutions. Its API is well documented and is supported by an active community of web developers.

DHTMLX Suite - This JavaScript library has both free and premium versions and is used by lot of professional web developers. The interface elements provided by this library are extremely eye-catching. It also includes a visual designer with drag-n-drop support to quickly make impressive web apps for your business website. It also includes a free HTML5 framework for making impressive mobile-friendly websites. The sheer volume of advanced web interface controls offered by this library can easily crush any other free alternative you may be using currently. You can also avail professional support to leverage the power of this intuitive UI library.

CSS3 PIE - One of the biggest pains of web developers is to make their websites compatible with different versions of Internet Explorer. This helpful library lets you implement several advanced CSS3 effects even for old IE versions. This way, visitors viewing your website through one of the old IE versions can see the web page in its original format without any kind of distortion. Adding this IE-specific CSS code does not affect the performance of your website. Through dozens of demo examples and documentation, you can easily apply IE-friendly visual transition effects on the key pages of your website. It's a must-have library for every web developer.

SproutCore - This is yet another powerful JavaScript library to build rich and interactive websites in quick time. It's not just the rich collection of web interface components, but the support for custom themes makes it a very useful framework. Each interface component in the library can be completely customized and extended as per your website requirements. The interactive elements created through this library are mobile-friendly as well and do not hang while the visitor is using the component. It also has complete support for HTML5 code so that you can include advanced interface elements without any need to write the complex and heavy code.

Knockout - As the name implies, this JavaScript library is fully capable of defeating any competition. It is exclusively designed for building rich web interface elements with minimum efforts. Its state-dependent model automatically changes the appearance of interface elements as the data associated with the changes in the back end. Web developers involved in large projects must use this library as it has a powerful inbuilt mechanism of dependency tracking so that the code can be managed, debugged and optimized with ease. It also lets you easily create templates for heavily used interface web elements to quickly reuse them again.

jQuery TOOLS - This library is also used by several large websites to power their visual elements. The good thing about this library is that the design created through it renders well on IE6 as well. The base library file size is very small (4 KB) and doesn't put any kind of load on your existing code base. Some of the common or frequently used elements in this library can be accessed easily through a free content delivery network to speed up the rendering of a web page. All the interactive interface elements created through this library are completely responsive. You can also perform event handling of interface elements through this library.

Animate.css - The name of this library perfectly justifies its functionality. Web developers must use this library while designing sign up forms and similar other sections where input fields and buttons are used on the web page. It lets you apply a large number of transition effects on interface elements to give a better user experience to the visitor. The library itself is tiny in size but the results are simply awesome. The visual effects applied through this library can increase your conversion rates significantly. But, you must take care of not overdoing it as it may backfire and annoy the visitors. I've used this library for several web projects.